After 20 years of operation of Tianhuangping pumped storage power station, the water conveyance system was emptied to overhaul diversion tunnel during the upgrade and renovation of ball valves for 6 units, which eliminated safety hazards. During the overhaul, the water leakage treatment method was innovated, the intelligent UAV was first used to inspect deep inclined shaft, the concentrated leakage points were treated by chemical grouting and cement grouting, and the concrete peelings were re⁃paired without formwork, providing reference for similar projects.

pumped storage power station, overhaul of empty high-pressure diversion tunnel, UAV inspection, grouting, concrete repair

天荒坪抽水蓄能电站投运20年后，在6台机组球阀升级改造期间放空输水系统，对输水道等进行了大修，以消除安全隐患。大修过程中，创新漏水处理方式，首次利用智能无人机检查深斜井，采用化学灌浆和水泥灌浆治理集中射水点，免立模修复混凝土掉块缺陷，为类似工程提供参考。

抽水蓄能电站, 高压输水道放空大修, 无人机检查, 灌浆, 混凝土修复